The present invention relates to a polyarylene sulfide resin composition. More particularly, the present invention relates to a polyarylene sulfide resin composition which has improved impact resistance and toughness and is useful in a wide range of applications as an engineering plastic.
Recently thermoplastic resins which have high heat and chemical resistance and excellent flame retardance have been demanded as the materials for components of electrical or electronic appliances, automobile devices or chemical instruments. Polyarylene sulfide resin represented by polyphenylene sulfide is one of the resins satisfying this demand inasmuch as the resin is inexpensive relative to its excellent properties. The demand for the resin has thus increased.
However, polyarylene sulfide resin has a fundamental disadvantage in that it has poor toughness, is brittle, and has insufficient mechanical properties represented by impact resistance.
For the purpose of solving this problem, for example, (1) a method of adding a reinforcement such as glass fiber or carbon fiber and (2) a method of adding other polymers have been employed.
However, these methods have not been satisfactory owing to their inherent problems.
Namely, method (1) provided a resin composition which is inferior to other engineering plastics such as polyacetal, PBT, polysulfone or polyether sulfone with respect to elongation and toughness and therefore is usable only in a limited field, although the composition has remarkably improved strengths, stiffness, heat resistance and dimensional stability to be useful as an engineering plastic. Although many proposals have been made with respect to method (2), the compositions obtained according to the proposals generally exhibit a lowered thermal deformation temperature and the present inventors have found that few of the proposals are sufficiently effective. Among the proposals, the addition of an olefin copolymer comprising an .alpha.-olefin and a glycidyl ester of an .alpha.,.beta.-unsaturated acid described in Japanese Patent Laid-Open Nos. 154757/1983, 152953/1984, 189166/1984 and 198664/1989 is recognizably effective in overcoming the above disadvantages. However, the compositions thus improved are yet insufficient for some uses requiring toughness and impact resistance and therefore are required to be further improved in many cases.
Further, Japanese Patent Laid-Open No. 155462/1984 discloses a process of adding a polyamide resin and an epoxy resin to a polyarylene sulfide resin. However, this process is also insufficient, because the obtained molded article causes bleed-through and has a poor surface condition and the composition exhibits remarkably low stability in a molten fluid state.